Image source: Best Random Stuff, Mt. Baigong
Mt. Baigong is weird for a couple of reasons. First, it's more a hill than an actual mountain. There are three caves near the base with triangle shaped openings. Inside the caves are pipe-like structures where there couldn't possibly be any man-made pipes.
Image Source: Ancient Wisdom, Baigong Cave
These tubes range in size from a needle to 16 inches in diameter. Some of them stretch from deep inside the mountain to a salt water lake 260 feet away. This is not a populated area. These pipes are not human in origin.
Image Souce: Ascension EarthBaigong pipes
So where did they come from? Alien plumbers? Probably not. The composition of these so-called pipes turns out to be 92% common mineral and metals and 8% unknown, but don't grab your aluminum foil hat yet.
Scientists think these "pipes" are fossils of tree roots. These roots underwent both pedogenesis (turning plant matter into soil) and diagenesis (turning soil into rock). So it's not a mammoth alien organ, which would have been cool.
(Information adapted from Atlas Obscura Baigong Pipes and Ancient Wisdom Baigong Pipes.)
Ever heard of these pipes before? Ever been to China? Did you have to cheat a bit on your Q word?